1. Field of the Invention
The invention relates to a baking oven comprising a baking chamber; a recirculation air heater which comprises a burner with a combustion chamber and a heat exchanger disposed downstream of the combustion chamber in the way of the re-circulation air.
2. Background Art
A baking oven of the generic type known from U.S. Pat. No. 5,617,839 comprises a cross-flow operated heat exchanger. To this end, a flue gas supply channel is disposed downstream of the combustion chamber; heat exchanger tubes extending parallel to the combustion chamber and transversely to the flow of re-circulation air discharge from the flue gas supply channel. They are connected to a deflection box from which again a second bunch of heat exchanger tubes discharges, opening into a flue gas discharge channel. Connected to the latter is a flue gas tube which leads to a chimney. The heat transfer effect leaves much to be desired. Considerable pressure drops are occasioned by the multiple deflections. The high number of heat exchanger tubes and the welding joints conditioned thereby render manufacture complicated and expensive, and moreover there is a high risk of weld seam fissuring, as the entire heat exchanger is problematic with a view to stress-corrosion conditioned by heat expansion.